Pain management in cancer patients

Dr. T. SujitConsultant Radiation OncologistCComprehensive CCancer CCare NNetwork

Pain is inevitable …… Suffering is optional

Pain – Just like Love….

• “Pain is whatever the experiencing person says it is, existing whenever he/she says it does.”

- Margo McCaffery, 1968

• An unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage.

- International Association for the Study of Pain (IASP)

Do all cancer patients suffer pain ?

• Moderate to severe pain experienced by 40% to 50% of cancer patients.

• Very severe pain experienced by 25% to 30% of cancer patients .

• 80% of terminal stage cancer experience moderate to severe pain

Cancer related pain – overview.

• Causes : – Infection– Tumor related

– Nervous system, bone, visceral, mucosal

– Treatment Related– surgery, radiation therapy, chemotherapy, interventional

procedures

• Types :– Nociceptive : pain signals from nerve endings– Neuropathic : damage to nerve fibres.

Diagnosis

• Detailed history :– Location ; single or multiple– Onset and duration ; variation.– Characterisation of pain– Aggravating and relieving factors– Effect of medications– Effect of pain on patient’s life.

Imminent fracture of long bones

• The score is a composite of the site (weight bearing status), pain, size, and lytic/blastic.

Score more than 8 = requires surgical stabilisation

Vertebral metastases

• Class I – III : Non-surgical management.• Class IV and V : Surgical management first.

WHO PAIN LADDER

• Developed in 1986 to help primary care physicians.

• Inexpensive drugs

• Legitimised the use of Morphine

• Oral administration of analgesics

• Analgesics should be given at regular intervals.

• Analgesics should be prescribed according to pain intensity as evaluated

by a scale of intensity of pain.

• Dosing of pain medication should be adapted to the individual.

• Analgesics should be prescribed with a constant concern for detail.

Shortcomings of WHO ladder

• Acute pain Vs Chronic pain• Cancer pain Vs Non-cancer pain• Newer drugs

– Tramadol, Oxycodone, Buprenorphine other adjuvants like Gabapentin, anti-depressants etc.

• Newer delivery methods– Transdermal patches– Infusion pumps

Adapted WHO pain ladder.

Radiation and pain relief

• Effective for Nociceptive and Neuropathic pain• Effective for mild to moderate and severe pain• Pain relief starting from within 24 hrs.• Complete effects seen after 1 - 2 months.• Brings about alleviation of other associated

symptoms – tumor swelling, anxiety and depression, appetite.

How does RT reduce pain ?

• Cell kill – reduced tumor size and pressure effects

• Endothelial damage of micro-vasculature – reduced blood flow.

• Reduces edema• Reduces pain related neuro-transmitter concentrations

• Bone – promotes re-mineralisation leading to structural stability.

When should a patient receive RT for pain ?

• No fixed guideline until recently.• Prophylactic RT for pain – DEFINITELY NO ROLE• Early onset pain ?

– Drugs Vs RT Vs Bisphosphonates ?– Drugs Vs RT + Bisphosphonates ?

• Vertebral mets Vs Non-vertebral mets

• American Society for Radiation Oncology (ASTRO)• Third International Consensus Conference on

Palliative Radiotherapy.

Single Vs Multi-Fraction

Single Vs Multi-Fraction

• Nearly identical outcomes with regard to pain relief.

• 20% of patients required re-treatment at a later date when treated with single fraction.

• No guideline as to when to be re-treated or dose for re-treatment; suggests clinical trial setting.

SBRT for pain relief

• Should not be used as the primary treatment for vertebral / spinal cord lesions.

• Can be used in a clinical trial setting for re-irradiation of vertebral / spinal cord lesions.

Hemi-body Irradiation

• For multiple lesions, when facilities for radionuclide therapy is un-avaialble.

• More suited for lower hemibody than upper.• Ideally treated using 6MV photons or higher• Keep lung dose to < 6 Gy for upper HBI

Bisphosphonates and RT

• “Bisphosphonates and RT can be given concurrently.”

• Synergistic effect – Zoledronic acid pauses the cells in G2M phase.

• Use of Bisphosphonates does not obviate the need for RT.

Radiopharmaceuticals

• Use of Radiopharmaceuticals does not obviate the need for EBRT.

• Ideal for osteoblastic, multi-focal and wide-spread disease.

Vertebral mets : RT Vs Sx

No prospective data are available to suggest that the use of either kyphoplasty or vertebroplasty obviates the need for EBRT in the management of painful bone metastases

International Bone Metastases Consensus Working Party 2012